Hi! I'm knitting a bag for my sister and am running into problems with one of the rows. 170 stitches are on the needle and the row instructions are k1, p1, *k4, p2, [p2tog, k1b, yo, p3] 3 times, p3; rep from * to last 6 sts, k4, p1, k1. end with 170 stitches. my problem is that with the p2tog, k1b, yo, i end up with a 1 stitch increase every time I do it... that comes out to 18 extra stitches! could any one help me out?

The KH glossary says this abbreviation means knit one through the back loop (as Ingrid said). However, Lion Brand says that this (k1b) usually means knit one below. The more common abbreviations for knit one through back loop are kbl, k tbl, or K1 tbl.

OP: You might want to look at your pattern to see if it explains what this abbreviation means.

Lion Brand says that this (k1b) usually means knit one below. The more common abbreviations for knit one through back loop are kbl, k tbl, or K1 tbl.

OP: You might want to look at your pattern to see if it explains what this abbreviation means.

Those are the abbreviations I'm familiar with, but that comes with the disclaimer of severely limited pattern reading experience. Hopefully the pattern in question has notes that clarify that abbreviation in the context of the pattern.